Tag: kafbat

Kafbat – OAUTH With RBAC

I encountered a challenge with a Kafka management tool — it supports SSO, and I was able to get an OAUTH connection set up to control what users could see when logging in through the UI, but the API component didn’t extract information from the bearer token and there was nothing in the rbac mapping to allow the bearer-token client ID to access anything.

Updates to allow the /api components to be authenticated by simple bearer tokens and a client ID mapped into a role are at https://github.com/ljr55555/kafka-ui

AuthorizationController.java was updated to properly support non-browser, machine-principal auth.

Added/fixed:

  • avoids null failure when authentication.getName() is missing
  • resolves principal name from alternate attributes such as:
    • client_id
    • sub
    • username
  • updated displayed permissions logic so /api/authorization uses the same effective RBAC matching idea as the backend

Result

/api/authorization now works for bearer-token API callers and shows:

  • username = client ID
  • populated permissions list

AccessControlService.java

Added support for API bearer-token principals

Previously, getUser() only worked when the authenticated principal was a RbacUser, which covered the browser/user flow.

Now it can also derive an AuthenticatedUser from opaque-token authenticated principals by extracting:

  • principal name
  • group-like values from attributes/authorities if present

Updated role matching logic

Previously, role matching was only role name matches one of user.groups(). Now it also supports role name matches user.principal(). That enables RBAC binding directly to the API client ID.

Result

RBAC now works for:

  • normal browser users via groups
  • API bearer-token callers via client principal name

DynamicConfigMapper.java

Fixed a mapper bug.

Before

The method mapping resource server config created a populated OAuth2ResourceServerProperties result object but always returned null.

After

It now returns result.

Result

Dynamic/config mapping for resource-server settings no longer silently discards the mapped object.

Build/package note

To preserve the browser UI, the jar needs to be built with frontend included — which you know if you read the doc … or you take my route, start it all up, test the API successfully, and then get baffled that the user UI throws 


        bash./gradlew clean assemble -Pinclude-frontend=true

application.yml

server:
  port: 8443
  ssl:
    enabled: true
    key-store: file:/etc/kafkaui/certs/kafbat.rushworth.us.p12
    key-store-password: ${KEYSTORE_PASSWORD}
    key-store-type: PKCS12
    key-alias: kafbat

auth:
  type: OAUTH2
  oauth2:
    client:
      pingfed:
        client-id: ${OAUTH_CLIENT_ID}
        client-secret: ${OAUTH_CLIENT_SECRET}
        scope:
          - openid
          - profile
          - email
        client-name: oauthclient
        provider: oauthclient
        redirect-uri: https://kafbat.rushworth.us:8443/login/oauth2/code/oauthclient
        authorization-grant-type: authorization_code
        issuer-uri: https://login.example.com
        jwk-set-uri: https://login.example.com/pf/JWKS
        authorization-uri: https://login.example.com/as/authorization.oauth2
        token-uri: https://login.example.com/as/token.oauth2
        user-info-uri: https://login.example.com/idp/userinfo.openid
        user-name-attribute: username
        custom-params:
          type: oauth
          roles-field: memberOf

    resource-server:
      opaque-token:
        client-id: ${OAUTH_CLIENT_ID}
        client-secret: ${OAUTH_CLIENT_SECRET}
        introspection-uri: https://login.example.com/as/introspect.oauth2

kafka:
  clusters:
    - name: test
      bootstrapServers: ${KAFKA_BOOTSTRAP_SERVERS}

roles.yml

rbac:
  roles:
    - name: "admins"
      clusters:
        - test
      subjects:
        - provider: oauth
          type: role
          value: "CN=KafbatAdmins,OU=SecurityGroups,DC=example,DC=com"
      permissions:
        - resource: applicationconfig
          actions: all

        - resource: clusterconfig
          actions: all

        - resource: topic
          value: ".*"
          actions: all

        - resource: consumer
          value: ".*"
          actions: all

        - resource: schema
          value: ".*"
          actions: all

        - resource: connect
          value: ".*"
          actions: all

        - resource: ksql
          actions: all

        - resource: acl
          actions: [ view ]

    - name: "${OAUTH_CLIENT_ID}"
      clusters:
        - test
      subjects:
        - provider: oauth
          type: user
          value: "${OAUTH_CLIENT_ID}"
      permissions:
        - resource: applicationconfig
          actions: all

        - resource: clusterconfig
          actions: all

        - resource: topic
          value: ".*"
          actions: all

        - resource: consumer
          value: ".*"
          actions: all

        - resource: schema
          value: ".*"
 
        - resource: connect
          value: ".*"
          actions: all

        - resource: ksql
          actions: all

        - resource: acl
          actions: [ view ]

docker-compose.yml

services:
  redpanda:
    image: redpandadata/redpanda:v25.1.2
    container_name: redpanda
    command:
      - redpanda
      - start
      - --overprovisioned
      - --smp=1
      - --memory=1G
      - --reserve-memory=0M
      - --node-id=0
      - --check=false
      - --kafka-addr=PLAINTEXT://0.0.0.0:9092
      - --advertise-kafka-addr=PLAINTEXT://redpanda:9092
    ports:
      - "9092:9092"

  kafbat-ui:
    image: ghcr.io/kafbat/kafka-ui:latest
    container_name: kafbat-ui
    restart: unless-stopped
    depends_on:
      - redpanda
    ports:
      - "8443:8443"
    volumes:
      - ./config/application.yml:/etc/kafkaui/application.yml:ro
      - ./config/roles.yml:/etc/kafkaui/roles.yml:ro
      - ./certs:/etc/kafkaui/certs:ro
    environment:
      SPRING_CONFIG_LOCATION: file:/etc/kafkaui/application.yml
      SPRING_CONFIG_ADDITIONAL_LOCATION: file:/etc/kafkaui/roles.yml
      KEYSTORE_PASSWORD: REDACTED
      OAUTH_CLIENT_ID: REDACTED
      OAUTH_CLIENT_SECRET: REDACTED
      KAFKA_BOOTSTRAP_SERVERS: redpanda:9092